1. Field of the Invention
This invention relates to a process for monitoring the synthesis of cellulose aminomethanate which has utility in the manufacture of cellulose film, such as sausage casing and cellulose films.
2. History of the Prior Art
The replacement of viscose dissolved, modified cellulose film with the use of ammonia derivatives, such as urea, reacted with cellulose to form a soluble product is a technology which has been gaining acceptance in the sausage casing industry. The use of such materials, in replacement of the traditional viscose regenerated cellulose process, is preferable as by-products are easily managed and do not appear to represent significant environmental impact. U.S. Pat. Nos. 1,771,461; 2,134,825; and 2,129,708 comprise some of the early work in this technology and demonstrate that film products are obtainable. Though the final products formed showed potential for use as a film, it wasn't until U.S. Pat. No. 4,789,006 that film products were produced using urea and cellulose for use as sausage casings.
Various different terminology has been used to describe the products of cellulose and urea, such as cellulose aminoformates, cellulose carbamates, cellulose aminomethanoate and cellulose aminomethanates as adopted in U.S. Pat. No. 4,789,006. To deter further confusion, the products formed with cellulose and urea as presented in the above patents and hereinafter will be referred to as cellulose aminomethanates.
With recent improvements in cellulose aminomethanate technology, such as those described in U.S. patent applications Nos. 365,272 and 365,267 filed on even date herewith, entitled Cellulose Aminomethanate By Acid Neutralization (M. Rahman), Preparation of Cellulose Aminomethanate (M. Rahman and D. Bridgeford) and Cellulose Aminomethanate by Ion Exchange Extraction (D. Bridgeford), each herewith incorporated by reference, the manufacture of cellulose aminomethanate product has become more convenient and suitable for use in the large volumes required for the sausage casing industry. Problems still exist however, in the manufacturing process, occasioned by the difficulty of controlling the extent of reaction that takes place between the urea and the cellulose structure in forming the cellulose aminomethanate. Thus there is a need for a method of monitoring the urea/cellulose reaction which will allow increased control over the reaction to improve consistency and product quality in the manufacturing process.
It is an object of this invention to improve the process for the formation of cellulose aminomethanate by providing means for monitoring the urea/cellulose reaction.
It is another object of this invention to provide a cellulose aminomethanate material having improved processibility.
It is a further object of this invention to provide a convenient means for processing urea intermingled cellulose which is being treated by heating.